Megahertz-rate ultrafast X-ray scattering and holographic imaging at the European XFEL

Abstract

The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL are presented. The experimental capabilities that the SCS instrument offers, resulting from the operation at megahertz repetition rates and the availability of the novel DSSC 2D imaging detector, are illustrated. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range.

Symmetry-dependent ultrafast manipulation of nanoscale magnetic domains

“…The X-ray scattering is collected on the DSSC 2D detector, able to match the repetition rate of the XFEL [35]. The DSSC records data at twice the X-ray repetition rate in order to collect so-called "dark" data frames in between pulses for the best background correction [36]. The sample to detector distance is fixed to 3 m.…”

XFEL Beamline Optical Instrumentation for Ultrafast Science

“…The macrobunch structure of the Eu-XFEL perhaps presents the most challenging conditions and therefore requirements of an optical laser source to support ultrafast studies. The development and operation of the high-end burst laser system at Eu-XFEL − is a good example of current technology and limits to application. , The PP laser system is capable of running up to a 4.5 MHz repetition rate, and the fundamental was designed to be at 800 nm, supporting pulse durations of as short as 15 fs in the fundamental. Frequency conversion, besides SHG and THG, is done using conventional colinear OPAs that can support up to a 1.1 MHz repetition rate at Eu-XFEL.…”